Kuva: Negin Pournoori
In his doctoral dissertation, Reza Jafari developed a new class of engineered composite coatings by combining an aluminium alloy with quasicrystal particles via a solid-state process known as cold spraying. In this process, micrometre-sized particles are accelerated to supersonic velocities, bonding upon impact to form a dense, thick deposit without the thermal damage typically associated with conventional, melting-based manufacturing methods. This method enables the fabrication of coatings that are significantly harder, more wear-resistant and more structurally reliable than non-reinforced aluminium alloy coatings. At the same time, this approach makes it possible to use quasicrystals in a practical manner despite their inherent processing challenges as a standalone material. Beyond fabricating the coatings, Jafari systematically investigated their structure from the macroscopic scale down to the nanoscale using advanced microstructural characterisation techniques. This made it possible to establish a direct link between processing, structure, and performance by correlating how impact-induced deformation, bonding, and microstructural evolution contribute to the enhanced properties.
The doctoral dissertation of MSc (Tech) Reza Jafari, in the field of Materials Science and Engineering, titled Cold-Sprayed Aluminum Alloy-Quasicrystal Composite Coatings: Correlative Structural Characterization and Functional Performance, will be publicly examined at the Faculty of Engineering and Natural Sciences of Tampere University on 17 April 2026.
The opponents will beProfessor Bertrand Jodoin from the University of Ottawa, Canada, and Professor Peter Hedström from KTH Royal Institute of Technology, Sweden. The custos will be Professor Minnamari Vippola from the Faculty of Engineering and Natural Sciences, Tampere University.